Electrodeposition of metals



July 14, 1925.

T. W. S. HUTCHINS ELECTRODEPOSITION OF METALS Filed Sept. 2, 1.924 2 Sheets-Sheet 1 July 14, 1925. 1,545,561

T. W. S. HUTCHINS ELEGTRODEPOSI TION OF METALS Filed Sept. 2, 1,924 2 Sheets-Sheet 2;

Patented July 14, 1925.

UNITED STATES PATENT OFFICE.

ELEOTRODEPOSITION OF METALS.

Application filed September 2, 1924. Serial No. 735,483.

To all whom it may concern:

Be it known that I, THOMAS WILLIAM STAINER HUToHINs, a subject of the King of Great Britain and Ireland, and resident of Davenham. Northwich, in the county of Chester. England, have invented certain new and useful Improvements Relating to the Electrodeposition of Metals, of which the following is a specification.

This invention relates to the electrodeposition of metals.

The objects of my present invention are to provide a more efiicient construction and arrangement of the filtering and recuperative apparatus in order to minimize acidlfication of the electrolyte due toaeration, and of the electrolyzer to obtain a satisfactory deposit of metal in an economical commercial manner.

My invention comprises the improved arrangements ofelectrolyzing plant and of the electrolyzing vats or cells as hereinafter described and claimed.

Referring to the two accompanyingsheets of drawings Figure 1 is a general view of an electrolyzing plant constructed and arranged inone convenient form in accordance with my invention.

Figure 2 is a detail sectional elevation, and Figure 3 a part plan and part sectional plan view of a depositing vat or cell constructed in one convenient form in accordance with my invention.

The same reference letters in the three views indicate the same parts.

The electrolyzing plant comprises in the example illustrated, electrolyzing vats or cells, a, b, a filter apparatus 0, and recuperators or absorbers d, e, through which electrolyte is circulated by a pump f. A by pass g is arranged in conjunction with the recuperator 6, so that the electrolyte leaving the recuperators need not all be passed into the filter apparatus a, but can be returned to the vessel 7:. from which the pump f is fed. An adjustably loaded valve Z is provided at the base of the by-pass pipe 9 and such valve will not open. unless t ere is a predetermined head of liquid above it.

I By this means I ensure that theby-pas g 'is'm'aintained fullof electrolyte, and it is only when the pressure head in the recuperators increases due to the electrolyte rising up the vent pipe 5 when the amount of electrolyte passing to the filter 0 is less than that being pumped into the recupel'ators by the pump f, that the valve opens. This occurs when one or more of the depositing vats or cells is put out of service. It will be seen therefore that with several electrolyzing vats fed by the one filter c and series of recuperators, if any vat or vats be put out of action, then though the full quantity of electrolyte may be circulated through the recuperators, a proportion only of the electrolyte may pass through the filter to meet the requirements of the vat or vats in service. It will be noted that only the electro lyte which goes to the electrolyzers is filtered and therefore the duty required of the filters is always proportional to the electro-deposition taking place. The aforesaid arrangement provides for an independcut or supplementary circulation within the recuperators without passing through the filters.

Thefilter a may be ofany usual type- Preferably it is built up from a number of sections which may consist of frames with filtering material in sheet form secured thereon. The electrolyte passes from the outside to the inside of .each section or frame so that each of the latter constitutes an lndependent unit. The electrolyte enters the filter at y and leaves at k. If the valve m in the supply pipe be closed, the valve 11. also closed and the valves 0 and p opened, the direction of flow through the filter can be reversed to remove deposits from the filtering medium and discharge them through the sludge cock 1).

It is important in many cases, especially in the case of iron, that the cathode q (Figure 2) should be specially carefully protected from small solid particles, especially carbon. I therefore circulate the carefully filtered electrolyte so that there is, in the cells a and 6, always a tendency to flow from the cathode chamber 1- to the anode chamber a, so that there is no possibility of particles set loose at the anode compartment getting to the cathode.

- Each electrolyzing or depositing vat comprises a vessel 21 (see Fi res 2 and 3) with an electrolyte inlet to lsposed in the base thereof. A cylindrical diaphragm 'v extendsa complete plant and several recuperators upwards from the base around the inlet to form the cathode chamber, the cathode being a cylinder or mandrel q rotating on a vertical axis and having a flange or collar w at its upper end which rests upon a pulley a: rotated by a rope or other means. The weight of the mandrel ensures its being rotated by the pulley :11. Electrical connection with the mandrel is effected by the brushes 52 carried from a ring a secured to a hinged plate 2 to which the electrical lead is connected. The brushes bear with spring pressure upon the top of the mandrel so that effective electrical connection is maintained therewith in service. 3 is a stop to support the hinged plate 2. By raising the latter, the mandrel can be freely withdrawn from the vat without releasing any connections. The diaphragm v is only semiporous, or Very little porous to the mechanical passage of the electrolyte and it causes the entering electrolyte to travel upwards therethro'ugh and over its upper end into the anode chamber .9. The electrical conductor for the anode or anodes is constituted by a lead or like liner t upon the vessel t, the said liner being insoluble in the electrolyte. The space between the liner and the diaphragmis filled in with metal (which may be in scrap form) and/or ore similar to the metal being deposited. In this case the liner would act as conductor for conveying current to the scrap and/or ore, the latter in consequence acting as the anode. The electrolyte which rises through the cathode chamber passes downwards throu h the anode chamber and leaves the latter t rough one or more orifices leading to overflow pipes as 4 extending upwards to the desired height and delivering into a trough 5 from WlllCh the electrolyte flows to a vessel 6. Outflow from said vessel is controlled by a float operated valve 7 which opens to allow electrolyte to return to the vessel It supplying the pump f only when the vessel6 is nearly full. I thus prevent frothing or aerated .electrolyte passing to the vessel It. There is no dropping of the electrolyte through space which causes breaking upand aeration of the electrolyte and the resultant acidification thereof, but a steady flow inthe trough 5 and a steady descent through the vessel 6. There is always a certain amount of acidification of the electrolyte due to its exposure to the atmosphere, but this is corrected in the recuperators and in the electro lyzin'g vats. Metal or ore may be placed in the vessel It also tobe absorbed by the'electrolyte;

In Working the plant, the supply of scrap mealand/or ore is maintained in the vats at by adding, the same at intervals intothe anode chambers.

A series of vats as at maybe comprised inas d e be employed, any one or more of which may if desired be put out of service when required for replenishing the metal or ore therein and removing sludge.

I claim 1. In the electro-deposition of metals, the combination with depositing vats and recuperators through which the electrolyte is adapted to be circulated, of means permitting of the overflow of electrolyte from the said vats and its return to the recuperators without aeration, substantially as described.

2. In theelectro-deposition of metals, the combination with depositing vats and recuperators and filters, of means permitting the circulation and return flow of the electrolyte through and from the said vats and recuperators in steady streams without aera-. tion, substantially as described.

3. In the electro-deposition of metals, means preventing aeration of the electrolyte from the vats and recuperators comprising a pipe into which the electrolyte enters, and means operating to deliver electrolyte from the lower end of said pipe only when a predetermined head of electrolyte has accumulated, substantially as described.

4. In the electro-deposition' of metals, the means for preventing aeration of electrolyte claimed in claim 3 characterized in that said means includes a pressure operated delivery valve, substantially as described.

5. In the electro-deposition of metals, the combination with depositing vats, recuperators a supply pipe for the recuperators and filters, of a by-pass permitting the return without aeration of a portion of the electrolyte leaving the recuperators to the supply pipe of the recuperators without passing throu h the filters, substantially as describe%.

'6. In the electro-deposition of metals, the improved depositing vat comprising an anode constituted by scrap-metal and ore and an insoluble conductor in electrical contact with said metal or ore, a vertical cathode, a relatively nonporous diaphragm between said anode and' cathode dividing the vat into anode and cathode com artments, means admitting electrolyte to t e bottom of the cathode com artment and causing it torise over said dlaphragm on its way to the anode compartment, and means allowing the electrolyte to leave thev vat from the lower part of the anode compartment, substantially as described.

7. In" depositing vats or cells for the electro-deposition of metal, the combination of a packed anode consisting of metal and ore packed between a c'onductor anda relatively imperviousfilter diaphragm separating the anode from the cathode, with means-to cup ply filtered electrolyte to the cathode chamber from which it passes to and through the anode chamber, substantially as described. 8. An arrangement as claimed in claim 7 in which the ,vat is provided with a lead liner to make contact with the packing material constituting the anode.

9. In the electro-deposition of metals, the

improved depositing vat comprising a vertical mandrel on which the metal is adapted to be deposited suspended by a flange at its upper end which rests upon a rotating wheel or pulley by which the mandrel is rotated, and electrical brushes bearing on said flange to make direct electrical connection with the mandrel or cathode substantially as described.

10. In depositing vats or cells for the electro-deposition of metals as claimed in claim 9, mounting the electrical brushes upon a hinged member whereby the placing of the'mandrel into and its removal from the vat is facilitated, substantially as described.

11. In the electro-deposition of, metals, the improved depositin vat comprising a vertical mandrel on w ich the metal is adapted to be deposited sus nded by a flange at its upper end by w ich also-the mandrel is rotated, electrical brushes bearing on said, flange to make direct electrical connection therewith, a filter diaphragm surrounding said mandrel and constitutin thewall of the cathode chamber into whic electrolyte is fed at the lower end, the wall of the vat being provided with a metallic liner insoluble in the electrolyte forming the electrical conductor for the anode which is constituted by scrap metal and ore packed between the said liner and the diaphragm. In testimony whereof I have signed my name to this specification.

THOMAS WILLIAM STAINER HUTCHINS. 

